The development of the micrometer communication has not been a linear path, but the team believes that the work has provided a proof of concept when it comes to connect-ing a micrometer with the HoloLens headset in a way that is applicable to many other measurement-tools and computer-devices.
Initially, prototype development was done using a breadboard, and divided into two
munication between the Bluetooth-transmitter and the XRI-application.
With the Adafruit Bluetooth-device as a basis, the team started testing data-transmission of hard-coded data to .txt-documents through text-editors on mobile phones and PC’s due to limited accessibility of the HoloLens headset (see Appendix F). Accessibility of the micrometer was also limited at first, so the team tried to get as much informa-tion about the protocols as possible through testing when the micrometer was available and through e-mail correspondence with Insize. The most time-consuming part of the process was figuring out the protocol from the micrometer. This was due to multiple instances of miscommunication with Insize where received data sheets lacked crucial information that the team tried to fill in through trial and error. At the end, the team had to move from the initial plans on communicating with the micrometer with-out the Insize Bluetooth-devices to assembling a system around both the Insize-devices.
After finally getting data from the micrometer to the Adafruit-device, the focus was on reading data to the XRI-application and parsing it to float-values.
For the micrometer communication, a natural next step in development will be to get the protocol needed for the Adafruit-device to communicate with the micrometer directly.
This will make the design more compact and cheaper since the Insize Bluetooth-devices would not be needed anymore. This system will also work on a PC in the same way as the Insize Bluetooth-system does on its own, but without the need of a receiving external module connected to a computer.
Another option available is implementing standby-mode for the Adafruit-device, which will increase battery-life and decrease the frequency of down-time due to charging.
There are also unused potential in the Adafruit-device concerning data management.
Through simple coding, the device can save measurements temporarily, handle both metric and imperial units and communicate with the HoloLens using any ASCII-characters. An example of application can be to mount an undo-button to the Bluetooth-module, which can send a message to the HoloLens for it to delete the last measurement.
7.5 Fixtures
Creating the fixture prototype has been a timely and at times difficult task. As the project is dominated by software development and the group consists of three computer
the project start it was unsure if it was necessary to use fixtures for the system, as no one from the group had any particular experience with the HoloLens software and the precision of the alignment technology used. This created a task with very little frame-work and limits, which made it hard to start with anything specific from the beginning.
During the project period it showed to be a crucial implementation, as the object recog-nition software on the HoloLens proved to be inadequate as is.
The COVID-19 pandemic (see Sec. 4.3) made it particularly difficult to create anything physical as the school went into complete lock down, making it impossible for the group to create parts at campus and hard to order parts and tools (as metal profiles, screws, nuts, washers, etc.) from there as we weren’t able to physically see what was available.
This created a great deal of delay as we had a lot of back-and-forth communication with the campus representatives responsible for order and availability of materials.
The lock down also affected the project’s client, KDA, which became even stricter regarding access to their facilities. Therefore, the mechanical team, who normally have access to the facility wasn’t allowed on the premises for approximately two months. This limited the opportunity to talk to the machine workers there and asking them to help with manufacturing parts for the project. All this uncertainty made ordering parts for the project quite problematic, time consuming, and at times, impossible. Luckily, we were able to take advantage of our contact network and thereby borrow a 3D-printer for the remainder of the project period, making it possible to actually produce a physical product. Unfortunately, we also had some problems with the printer as it struggled to pull the filament thread through the extruder. Resulting in print failures (see Fig. 94).
(a) (b)
This was a production delaying problem and a lot of time was put into fixing it, taking time from other tasks that were directly project related. As shown in Fig. 95, it was necessary to open the printer head and take it apart for cleaning purposes, switching of almost defect parts, tightening springs, etc..
(a) (b)
Figure 95: Fixing the 3D printer
The last month of the project, the mechanical team was allowed back to KDAs facilities and get some manufacturing of some of the components done by the operators there.
Most of this was already communicated via e-mail, but it proved important to have the physical dialog to make sure that the schematics told the operator what exactly the group wanted for the final products.
As the prototype is finalized and manufactured, the team believes it shows a proof of concept that is presentable as a final product for the project. To follow up with the prototype we recommend that the client evaluates the fixture’s functions and continues the work on a fixture with the same functionalities more functional with the part sizes that is in their production process.
8 Conclusion
Can the quality control process at KDA (see Sec. 2.1.2) be improved in terms of effi-ciency and reliability with MR technology and Microsoft HoloLens? This was the initial question the team has faced with, which is also well-illustrated by the requirements ex-pressed by the customer (see. Sec. 2.2.1). Unfortunately, one cannot wrap up a 200 page report with a simple yes or no. The difficulty in doing so, of course, lies in the richness of the detail and nuances this project has been riddled with. So instead, the conclusion will present team’s main findings in broad stokes, in hopes that it gives a better insight into the project.
In-house testing showed that the efficiency can be indeed enhanced with a head mounted computer (HMC), such as HoloLens, and the XRI application substantiates this state-ment. Hands-free access to information in demand, wireless transmission of the mi-crometer measurements to the application, and digitization of the data transfer can do wonders for the inspectors, decreasing human errors and increasing convenience and speed of the entire process, while image capturing of the measurements with the built-in camera improves tracebility and documentation of the process. Fixing the com-posite panels in specific positions proved to be a crucial factor for the HoloLens’ object tracking software to function properly, while also giving the operator an easier working experience as the panel are locked in convenient positions for the measurement process.
With a proper introduction, the system is easy to use regardless of age and technical background, while meeting security standards of the client.
In contrast, there are still areas that require improvements before the product is ready for deployment in a wide scale industrial setting. The fixture components must be designed for a higher carry load, as the plastic components are fragile and varies a lot in quality as is. The fixture itself may be scaled to fit the panel sizes at KDA better and the mounting brackets for the working table (Bottom plate) may be changed for an easier deployment. First generation HoloLens has quite uncomfortable head-fit system and it is not suitable to be worn for very long at a time. Also, improvements in tracking accuracy are required to successfully reduce the possibility of human errors during the measurement process, and implement a guidance system that overlays AR content onto physical objects. Many of the shortcomings of the HoloLens 1 are rectified in the second generation of the device, HoloLens 2, and an evaluation of the new headset is earnestly recommended to draw a full conclusion on whether the improvements in tracking accuracy and other areas are adequate for the industrial usage.
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